Carburetor



Nov. 22, 1938. 1 CROCKETTI 2,137,665

GARBURETOR I Filed May 21, 1937 Inventor M unma- Attorneys Patented Nov. 22, 1938 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to carbureters, the general object of the invention being to provide means for improving the operation of the carbureter at idling and intermediate speeds.

This invention also consists in certain other features of construction and in the combination and arrangement of several parts, to be hereinafter fully described, illustrated in the accompanying drawing and specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to the accompanying drawing wherein like characters denote like or corresponding parts throughout the several views, and in which:--

Figure l is an elevation with parts broken away showing a carbureter constructed in accordance with this invention.

Figure 2 is a view of the inner end of the plug.

Figure 3 is a longitudinal sectional view through the plug.

In this drawing the body of the carbureter is shown A and the carbureter is provided with the usual passage I which leads the mixture to the cylinders of the motor, said passage being controlled by the throttle valve 2.

In carrying out my invention I provide means for controlling the flow of fuel from the low speed passage 3 into the passage I at the valve 2, such means including a plug 4 threaded in an opening at the discharge end of the passage 3 and having a chamber 5 therein into which the passage 3 discharges. The inner end of the plug is formed with a large port 6 and a smaller port 1, these ports connecting the chamber 5 with the passage 1 and a groove 8 is formed in the inner end of the plug and gradually tapers upwardly and downwardly from the large port 6 as shown in Figures 2 and 3, that portion of the groove below the port 6 being longer than the portion above the port as shown in Figure 2. A' needle valve 9 controls the port 6 and a similar valve 1 I] controls the port 7, these valves being threaded in holes in the plug and have coiled springs II on the outer portion for firmly holding them in adjusted position. The outer ends of the valves have kerfed heads so that they can be adjusted by a screw driver or the like.

As will be seen when the throttle valve 2 is closed some of the fuel can pass from the chamber 5 through the port 1 into the passage l to the engine 5 from the carbureter so that the engine can idle with the throttle valve closed. When the valve is slightly opened more of the fuel will pass through the port 6 and the groove 8to gradually increase the speed of the engine and this arrangement will give eflicient performance of the engine at speeds between idling and high speeds.

The groove 8 acts to prevent closure of the port 6 by the throttle when the throttle is slightly opened from a closed position.

It will, of course, be understood that the needle valves permit regulation of the amount of fuel passing through the ports 6 and 1.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts, provided that such changes fall within the scope of the appended claims.

What is claimed is:-

1. In combination with a carbureter having a main passage, a low speed passage and a throttle valve for controlling the main passage, a plug threaded in a hole in the carbureter at the junction of the two passages, said plug having a chamber therein into which the low speed passage discharges and said plug having a large port and a small port therein communicating the chamber with the main passage, needle valves carried by the plug for controlling the ports, the throttle valve when closed separating the ports with the small port on the engine side of said valve and the inner end of the plug having a groove therein into which the large port leads, said groove extending lengthwise of the passage and acting to prevent the large port being entirely closed by the throttle when the throttle moves slightly to open position from entirely closed position.

2. In combination with a carbureter having a main passage, a low speed passage and a throttle valve for controlling the passage of fuel through the main passage, a part having a large port and a small port therein connecting the low speed fuel passage with the main passage for permitting fuel to pass from the low speed fuel passage into the main passage, the small port leading into the main passage on the engine side of the throttle valve when the valve is closed and said valve when closed separating the ports, a needle valve for controlling the large port, a second needle valve for controlling the small port and that portion of the wall of the main passage to which the large port opens out having a groove therein extending lengthwise of the main passage and in communication with the outlet end of the, large port for preventing said large port being entirely closed by the throttle valve when said throttle valve moves slightly to open position from a fully closed position.

LYNN CROCKETT. 

